There are a great number of applications for small barrel type fuses, and more recently blade type fuses, which are inserted into spring clip receptacles. The most common of these is in the automotive industry where virtually every vehicle includes a plastic fuse block, made from phenolic or the like, with a plurality of fuses and fuse receptacles wired into the various electrical circuits of the vehicle to provide overload and short circuit protection therefor. Almost everyone is familiar with the glass barrel type fuses commonly used in the automotive industry. During the last several years, a new blade type fuse with a plastic body has been introduced and is now being used to replace the barrel type fuse on most all car lines. As these fuse blocks are not generally considered to be stylish, they are oftentimes placed in concealed locations, i.e. such as under the dash, which greatly limits their accessibility. As a result, when a fuse blows it can be quite inconvenient to remove the blown fuse and replace it with a new fuse. This is caused not only by the awkward location of the fuse block, but also by the small size of the fuse, and the relatively high contact pressure required to ensure reliable circuit operation in a low voltage, low amperage application.
There are presently available in the prior art several different kinds of devices suitable for inserting and removing barrel type fuses. One of these includes a one piece molded plastic tool with jaws on either end of the tool and a sliding metal clamp along the handle. The tool is used by clipping the plastic jaws over the barrel of a fuse, sliding the clamp down around the jaws to more firmly position them, and then pulling on the handle to remove the fuse. As can be appeciated, performing these steps can be somewhat inconvenient and time consuming when the fuse block is awkwardly positioned. Furthermore, there is always the danger of shattering the glass barrel of the fuse. Also, the tool does not function with the newer design blade type fuse.
Another tool in the prior art has a pair of opposing metal jaw members mounted in a plastic handle such that they may be opened or closed by rotating the handle with respect to the jaws. This tool is used by first positioning the jaws adjacent the barrel of the fuse, rotating the handle to tighten the jaws about the fuse (the barrel of the fuse restricting rotation of the jaws), and then pulling the tool to remove the fuse. This is also a somewhat complicated tool which can be quite expensive for the limited usefulness of a fuse puller. Furthermore, there is a normal reluctance to point metal jaws at an electrical device and use the jaws to work on an electrically hot device. As with the other tool, the fuse is removed by grasping the glass barrel near its midpoint which requires the user to overcome the spring force at both ends of the fuse and can result in breakage of the glass tube. After a glass tube is broken, it can be quite difficult to then remove the end caps of the fuse from between the jaws of the spring fuse clip.
To solve these and other problems, applicant has succeeded in developing a one piece molded plastic tool which can be used with either blade type or barrel type fuses, and which can remove and install either type easily and efficiently with lessened danger of breakage. The central or handle portion of the fuse puller is generally elongated and can be shaped to adapt to the hand of the user. At one end of the fuse tool, a pair of flexible tines extend in a generally colinear fashion and in opposition to each other, each tine having a barb with a beveled surface at the hand of the barb. Each barb extends inwardly somewhat to form a shelflike projection or tab which is adapted to rest against the lower surface of the raised shoulder on the hand of a blade type fuse. A stem extends generally colinearly with the handle and between the tines so that the head of the blade type fuse can be captured between the stem and tines. The tines are sufficiently resilient to press snap onto the enlarged head of a blade type fuse as it is inserted into its fuse clip, with the tablike projections of the barbs catching underneath the fuse's raised shoulder. A fuse may then simply be removed by withdrawing the tool and fuse from the fuse block. The tool may be used to insert a blade type fuse by sliding the head of the fuse sideways between the tines and stem and then reversing the procedure. Once the fuse is installed, the tool may be removed by a rocking motion to individually separate each tine from the fuse, or by sliding the tool sideways with respect to the fuse. The top surface of the stem is generally concave such that the barrel of a barrel type fuse can be pushed in between the tines and be captured between the tines and the stem to facilitate the insertion of the fuse into its fuse clip. As the flexibility of the tines is greater than the spring type fuse clip, the tool may be easily separated from the fuse without danger of damage to the glass type barrel.
As can be appreciated, all these above described functions can be achieved with the structure as shown at one end of the tool. These functions include both inserting and removing a blade type fuse and the insertion of a barrel type fuse. To aid in the removal of a barrel type fuse, the other end of the tool has a hooklike projection which can be molded right into the one piece tool. The hooklike projection is generally flattened so that it will fit down between the barrel of the fuse and the surrounding fuse block, pivoted 90.degree. underneath an end of the fuse, and then lifted or pulled away from the fuse block to remove only one end of the fuse. As can be appreciated, this requires substantially less effort than grasping the barrel type fuse closer to the center of its barrel as only one set of fuse clips need be separated to remove one end of the fuse. Once that end of the fuse is removed, the user may then simply grasp the exposed fuse end with his fingers and easily remove the other end with a lever type motion. Thus, with applicant's tool, either a barrel type and blade type fuse may be inserted and remove in a quick and easy manner. Furthermore, applicant's one piece tool may be injection molded in a single piece construction of a non-conductive material, such as a polycarbonate plastic, which greatly reduces the cost of manufacture. Further advantages and features of applicant's invention may be learned by reviewing the drawings and reading the description of the preferred embodiment which follows.